Web coating control

ABSTRACT

The following specification describes a method for applying a uniform oil coating of selected thickness to a steel web moving at variable speed past an absorbent roll, which coats the web with oil. The roll travels the same distance as the web and drives a counter for counting a predetermined number of web lengths irrespective of web speed. A selected quantity of oil is sprayed on the roll under control of a timer after a predetermined number of web lengths are counted to ensure that the quantity of oil sprayed corresponds to a predetermined web length for providing a uniform oil coat of selected thickness irrespective of web speed.

0 t 11 ate States Pate t 1151 3,649,348 Mozzi, Jr. Mar. 14, 1972 1 WEBCOATING CONTROL 2,813,485 11/1957 Harless ..101/366 [72] Inventor: Henry.1. Mozzi, Jr., Chicago, 111. [73] Assignee: Stewart-Warner Corporation,Chicago, 111. 3,301,699 H19 M0 "..1 7/1 1 l 4 3,416,489 12/1968 Hoffmann118/206 X [221 Wed: July 23, 1970 3,417,810 12/1968 Tiskus et a1...118/8 x [21] App1.No.; 57,584

Primary ExaminerAlfred L. Leavltt Related U.S. Application DataAssistant Examiner-Thomas E. Bokan v A1t0rney-Augustus G. Douvas,William .1. Newman and Nor- [62] D1v1s1on of Ser. No. 743,728, July 10,1968, Pat. No. ton Lesser [57] ABSTRACT [52] U.S. C1. ..117/111 D,101/366, 117/111 R,

117/127 117/135 1 17 2 1 3 3 1 3 The following specification describes amethod for applying a 1 18 /2 59 uniform oil coating of selectedthickness to a steel web moving 5 1 1m. 01. ..B44d1/02,B44d 1/34, 1344a5/08 at variable Speed P an absorbent roll, which coats the web [58]Field f Search 0117/1 R, 111 D, DIG. 2, 49, with oil. The roll travelsthe same distance as the web and 1 17/127; 118/8 11, 259; 101366 drivesa counter for counting a predetermined number of web lengthsirrespective of web speed. A selected quantity of oil is 56! ReferencesCited sprayed on the roll under control of a timer after a predeterminednumber of web lengths are counted to ensure that the UNITED STATESPATENTS quantity of oil sprayed corresponds to a predetermined weblength for providing a uniform oil coat of selected thickness ir-1,634,258 7/1927 Halpin ..118/259 X respective ofweb spemi 1,719,0177/1929 Moe et a1. ..lOl/366X 2,633,822 4/1953 Watterson, Jr. ..118/227 3Claims, 6 Drawing Figures PAIENT EBHAR 14 I872 SHEET 1 OF 4 INVENTOR mayJ. uozz: Jr.

A'lornu PATENTEBHAR 14 I972 SHEET 2 [1F 4 INVENTOR HENRY J. MOZZI Jr.

AHorlIOI PATENTEBHAR 14 I972 SHEET 3 [IF 4 INVENTOR HENRY J. MOZZI JrFIGS.

PATENTEDHAR 14 I972 SHEET L [1F 4 FIG.6.

INVENTOR HENRY J. MOZZI Jr.

WEB COATING CONTROL This application is a division of application, Ser.No. 743,728, filed July 10, 1968, now U.S. Pat. No. 3,590,778.

BRIEF DESCRIPTION OF THE INVENTION The invention relates to a system ormethod for coating webs and more particularly to the provision of an oilcoating of desired thickness on a variable speed moving metal web.

BACKGROUND OF THE INVENTION In rolling mills steel sheet is passedbetween rollers which roll the sheet or web to a desired thickness andthe sheet is then coiled. After the steel is rolled and before it iscoiled it is desirable to provide the sheet with an oil coat to avoidrusting and sometimes to provide a lubricating surface for subsequentoperations. Oil coatings are required for metals other than steel, andcoatings other than oil such as liquified waxes are also required foreither steel or other metals; but, in any event, the coatings areusually required to be uniform and of a selected thickness.

An arrangement providing a uniform coating is shown in U.S. Pat. No.3,301,699, issued Jan. 31, 1967. In that patent a plurality of sprayheads distributed across the width of the web are cyclically turned onand off in a desired sequence to spray an absorbent roll with oil whichuniformly coats the web.

In this arrangement the thickness of the oil coating depends on theamount of oil provided by the absorbent roll per unit area of the weband this in turn depends both on the spray time for the oil and the webspeed. One technique for controlling the coating thickness is disclosedin U.S. Pat. No. 3,416,489, issued Dec. 17, 1968 to Gunter F. M.Hoffman.

In this latter patent a timing relay is periodically actuated by arotating member keyed to the absorbent roll to spray oil on the roll fora time period determined by a clock setting. The web speed may range ashigh as 4,000 feet per minute to rotate the roll at approximately 2,000rpm. depending on the roll diameter. With a SO-to-l gear reductionbetween the roll shaft and the rotating member, only about two-thirds ofa second elapses between timing relay actuations, although the total orunit web length that passes the roll between timing relay actuations isconstant irrespective of web speed. With a total cycle time oftwo-thirds of a second, the spray time could be not much longer thanone-third of a second at high web speeds.

If the web started to slow, the one-third of a second spray timeprovided an excess amount of oil over the portion of the web passing theroll during that one-third of a second, since only a short web lengthpassed during that time portion. During the remainder or dry portion ofthe cycle a greater web length passed the roll than during thecorresponding dry portion when the web was running at high speed andtherefore under oiling would occur towards the end of that web portion.

If, on the other hand, the web was running at, for example, 2,000 feetper minute and a total cycle time of I /6 seconds was available betweentiming relay actuations, the spray time could be increasedcorrespondingly. Then, if the web was speeded up substantially, thespray time occurred while the greater portion of the total web lengthpassed the roll leaving an excess of oil for the portion of the webpassing during the dry or off time of the spray,

The most versatile arrangement would be to have both the spray cycle andthe dry or off cycle as short and as frequent as possible. Due to thefinite conditions required to generate and terminate the spray,one-third of a second for the spray cycle is about the shortestpractical cycle. Also, either a dry or wet cycle of very short durationcould create too much percent variation in the total length per cycle ifthe spray output or web speed varied. With a relatively large of? timethe web length per cycle is increased and slight variations in sprayoutput or web speed are not too critical.

Increasing the spray time is also desirable for many applicalions sinceas many as 3 to 6 seconds of spray time are needed, but this usuallyalso requires a substantial increase in the off time or dry portion ofthe web. Increasing the off time in a system of the type describedrequired increased gear reduction, which is unnecessary for many systemsso that gear reduction systems have to be tailored for differentapplications.

SUMMARY OF THE INVENTION In brief, the present invention utilizescounting apparatus to count the passage of a desired number of weblengths to provide a constant web length irrespective of web speedduring the dry or off portion of the cycle. The installation of thecounting apparatus avoids the necessity to tailor the gear reduction forthe needs of the system since it is inexpensive and is easily controlledto select any one of a wide variety of predetermined web lengthspermitting in turn the selection of a wide variety of spray times. Whena selected count is reached indicating the passage of a totalpredetermined web length, the spray is turned on under the control of aclock or timer to spray the web for a selected time. The countingapparatus is disabled during the spray so that the spray time can bevaried within wide limits irrespective of web speed and since the weblength passing the roll during the dry portion is constant, variationsin web speed do not radically alter the coating thickness.

Accordingly, it is one object of the present invention to economicallyprovide a more versatile method or system for coating a moving web witha coat of desired thickness.

It is another object of the present invention to provide an improvedsystem or method for uniformly coating to a selected thickness with oila metal web moving in a wide range of speeds.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevational view of atypical steel mill roll stand and a coating stand having coatingapparatus employing the principles of the present invention;

FIG. 2 is an enlarged fragmentary section view of the relevant portionof the coating assembly;

FIG. 3 illustrates the flexible shaft connections between the coatingroll and the pulse contact assembly;

FIG. 4 is an isometric view of the pulse contact assembly;

FIG. 5 is an isometric view of the instrument panel; and

FIG. 6 is a circuit diagram illustrating the circuits employed in theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I of thedrawings, a steel mill roll stand is indicated generally therein by thereference character 10. The stand comprises a rigid framework 12supported on a concrete base 14 with the frame having a pair of verticallegs 16 on each side of a steel web 18 passing between the leg pairs.

Journal blocks 20 and 22 are located between the legs 16 on each sidefor rotatably supporting rollers 24 and 26 respectively for rolling theweb 18 therebetween to a desired thickness. The axis of rollers 24 and26 lie in a common vertical plane and the pressure under which they rollthe web 18 is controlled by a pair of pressure rollers 28 and 30 underpressure supplied through a hydraulic cylinder assembly such as The web18, after passing between the rollers 24 and 26, is supported by rollerstand assemblies such as 34 spaced along a walkway 36 and is coated withoil by means of a coating assembly 38 and subsequently coiled at astand, not shown.

The coating assembly 38 comprises a conventional framework 40 straddlingthe web for adjustably supporting pairs of journal blocks such as 42 and44. The journal blocks 42 and 44 are adjustable along the vertical axisof the framework. Journal block 42 rotatably supports a coating roller46 of absorbent material such as described in the aforementioned U.S.Pat. No. 3,301,699 and adapted to engage one side of the web. Pressureon the rollers 46 and 48 is exerted along the vertical axis of theframework 40 by means of hydraulic assembly 50.

A housing or shroud 52 covers a peripheral portion of the coating roller46 to prevent the general dissemination of oil fumes and a conduit 54 atthe top of the shroud provides a controlled exit for the fumes. As seenin FIG. 2, oil to the roller 46 is supplied from a plurality of spraynozzles such as N1 and NX distributed axially along the roller 46 inrespective rows on opposite sides of a vertical plane passing throughthe roller axis. It will be appreciated, of course, that the lower roll48 can be an absorbent roll and the oil sprayed thereon.

The oil spray nozzles N1, etc, are supplied with oil from pumps throughconduit 56 and each nozzle is controlled by a respective solenoid valvesuch as V1 and SVX supported on brackets 58 together with the nozzles.The solenoid valves 8V1, etc., are controlled over an electrical cable60 extending to an instrument panel assembly 62 on the framework 40.

The instrument panel 62 includes a plurality of switches SW1 and S1 SXwith the latter operable for selecting the solenoid valves to beoperated. The panel also includes a plurality of lamps such as 64 forindicating operation of the solenoid valves and both a timer 66 and acounter 68. The counter 68 is arranged to be operated from a pulsecontact assembly 70 over an electrical cable 72 and the pulse contactassembly in turn is operated through a flexible shaft assembly 74.

The flexible shaft assembly 74 as seen in FIG. 3 comprises aconventional casing 76 encircling an elongate flexible shaft 78. Eachend of the casing 76 terminates in a ferrule 80 fastened to a respectivecap 82 on the contact assembly 70 andjournal block 42, respectively. Cap82 on block 42 has an opening coaxial with the axis of a shaft 84 thatcarries the absorbent roll 46. The corresponding end of the flexibleshaft 78 passes through the cap opening.

The noncircular flexible shaft end engages in a correspondingly shapedopening of a coupling element 86 press fit into the end of the shaft 84so that the flexible shaft 78 rotates at the same speed as the shaft 84and the roll 46. Since the roll 46 is moved by the passing web 18, theroll 46 in turn moves at the same speed as the web 18.

The other end of the flexible shaft 78 passes through an opening in thecap 82 on the pulse contact assembly '70. The opening is coaxial with ashaft 88 of the first gear of a gear reduction assembly or gear box 90in the pulse contact assembly 70. A connector 92 connects the respectiveflexible shaft end with the shaft 88 so that the gears of assembly 90are driven at a rate corresponding to the web speed. The gears in box 90conventionally provide a SO-to-l reduction between the input speed andoutput speed.

The assembly 70 comprises a U-shaped bracket 94 with a base plate 96straddling the legs of bracket 94 for supporting gear box 90 togetherwith a rotatable disc 98. The disc 98 is driven by the web 18 throughthe roll 46, shafts 84,. 78 and 88 and the gears in box 90. The disc 98carries a plurality of magnetic switch actuating assemblies 100distributed adjacent the circumference of disc 98 and extending axiallyfrom the disc. In this case six assemblies 100 are provided and each isadapted to operate a pair of contacts 102 (seen in FIG. 6) ofa reedswitch assembly 104 supported on plate 96 as each assembly 100 rotatespast the switch assembly 104. The contact assembly includes conventionalarc suppression apparatus and the contacts 102 are adapted to send apulse on each operation over leads 105 and 106 extending through cable72 to the counter 68.

The timer 66 and the counter 68 are manufactured by D. W. Bliss Company,736 Federal Street, Davenport, Iowa, under Model Nos. HP 515A6 and HZ172A6, respectively, and shown in bulletins 125 and 725, respectively.The timer 66 and counter 68 have a respective conventional cam C 1 andC2 (FIG. 6) and each includes a stop. Both cam and stop of the timer andthe counter are manually set or rotated to a desired position by arespective knob, seen in FIG. 5, and their position indicated on arespective dial. The cams Cl and C2 are then driven to a home positionas will be explained.

The cam C1 of the timer 66 is driven to its home position whenever atimer clutch magnet 110 and a timer motor M1 are energized while thestop remains in the set position. On

reaching the home position the cam C1 operates contacts CS1 and CS2 todeenergize the clutch magnet and motor M1. Deenergizing the clutchmagnet 110 permits a return spring to move the cam C1 back to theposition in which the stop has been set by the respective knob 108 sothat the cycle may be repeated.

The counter 68 also has a clutch magnet and operates on a similarprinciple as the timer 66 except that a stepping magnet 8M1 is used tostep the cam C2 incrementally from the set position to the home positionin response to pulses received over leads 105 and 106 from the pulsecontacts 102. In the home position the cam C2 operates contacts CS4 todeenergize the clutch magnet 120 and a return spring then returns thecam C2 to the position in which the stop is set by the respective knob108.

The circuit employing the timer 66 and the counter 68 for controllingthe spray nozzles N1, etc., is shown in FIG. 6 and generally identifiedby the reference character 130. The circuit includes the circuit for thetimer 66 and the circuit for the counter 68 with switches S1 SX shownfor selecting the solenoids 8V1 SVX and respective indicator lamps 64 tobe operated. It will be understood that the switches S1 SX are connectedto control as many respective solenoid valves as desired. For example,switch S1 may control solenoids SVI, SVla, SVlb and SVlc. The solenoidvalves SV1 and SVla and their respective spray nozzles may be located atthe op posite ends of one nozzle row and valves SVlb and SV1c in theopposite row. Similarly, switch SX may control solenoid valve SVX andSVXl in either opposite rows or at different positions in the same row.Other switches control either intermediate pairs of solenoid valves orindividual valves in each row. This enables the width of the spray to beselected for correspondence with the width of the web. It will also beappreciated that under some circumstances only one row of solenoidvalves and noules will be used.

The circuit for timer 66 includes the clutch magnet 110, which enablesthe timer motor M1 to drive the timer cam C1 during the period in whichsolenoids SVl SVX are operated. In this type of timer the cam C1 ismanually set to a desired position corresponding to the time which thesprays are to operate and the motor M1 drives the cam to its homeposition where it controls three sets of contacts CS1, CS2 and CS3.Thereafter, the cam Cl is reset to the desired position automaticallyunder control of the return spring as described for the purpose ofrepeating the cycle.

The circuit for counter 68 comprises the clutch magnet 126 for enablingsolenoid 5M1 to step cam C2 incrementally through a ratchet mechanism.That is, the cam C2 is set in a position corresponding to the desiredcount and as the solenoid SMl receives pulses from the pulse contacts102, solenoid SMl steps the cam C2 incrementally until the cam reachesits home position. 0n reaching the home position the cam C2 openscontacts CS4 and is reset to the set position under control of thereturn spring as described for the purpose of repeating the cycle.

The switches S1 SX are manually operated for the purpose of selectingthe solenoid valves SVl SVX for operation by the timer to spray the web.The selected valves depend usually on the web width so that, forexample, if a web of small width is to be oiled, only solenoids adjacentthe center of the solenoid valve and nozzle row are operated by closureof the corresponding switch, while if it is desired to operate allsprays all of the switches S1 SX are operated.

Briefly, the operation of the circuit is as follows. The switch SW1 isoperated to connect power through normally closed cam contacts CS4,counter clutch magnet contacts 124, to the clutch magnet 110 and thetimer motor M1, the latter being in shunt with indicator lamp LM, whichlights to indicate the timer is operated.

The clutch magnet 110 closes contacts 112 so that power is applieddirectly from switch SW1 through contacts CS1 to the timer motor M1 andthe magnet 110. Contacts 114 are also closed by magnet 110 so that poweris applied from cam contacts CS3 through the operated ones of switchesS1 SX to the respective solenoid valves SVl SVX in shunt with respectiveindicator lamps 64 to indicate the operated solenoids. The operated onesof solenoid valves SVl SVX open the oil supply to the respective spraynozzles and oil is delivered to the absorbent roll 46 and applied to theweb 18 to provide an oil coating initially to the web.

The timer cam C1 in the meantime is driven by the motor M1 towards thetimer home position and when the cam C1 reaches the same it openscontacts CS1 and CS3 and closes contacts CS2 before contacts CS1 open.Opening contacts CS1 opens one circuit to the motor M1 and openingcontacts CS3 deenergizes the spray solenoids SVl SVX.

Closing contacts CS2 extends power from switch SW1 to clutch magnet 120in shunt with indicator lamp LP which indicates the counter is inoperation. Clutch magnet 120 opens contacts 124 to open the originalcircuit to magnet 110 and motor M1 to deenergize the clutch magnet 110and motor Ml as soon as contacts CS1 open. The cam C1 resets undercontrol of the return spring to open contacts CS2 and close contacts CS1and CS3; however, since contacts 124 are open, the magnet 110 and motorMl do not reenergize at this time. The spray solenoid valves SVl SVXalso do not reenergize, since contacts 114 are open. Magnet 120 in themeantime stays energized over a holding circuit through contacts 122 andCS4 to prevent closure of contacts 124 and reenergization of magnet 110and motor Ml.

Power from switch SW1, contacts CS4 and 122 is now ex tended to thestepping magnet SMl each time contacts 102 close in response to eachpassage of one of the magnet assemblies 100 past the switch assembly104. The magnet SMl steps the cam C2 once for each pulse. The pulsecontacts 102 close at time intervals dependent on the web speed as itpasses the coating roll 46. Since the web length which rotates the roll46 an increment or angular distance necessary to operate contacts 102 isconstant, the number of pulses necessary to step cam C2 home isindependent of the web speed. A predetermined web length, therefore,passes the roll 46 in order to step cam C2 to its home positionirrespective of changes in web speed.

When cam C2 reaches its home position contacts CS4 open to deenergizethe clutch magnet 120 and the lamp LP Clutch magnet 120 opens contacts122 to prevent its further energization or further energization of thestepping magnet 120 and closes contacts 124. The cam C2 returns to itsset position under influence of the return spring and contacts CS4 closeto reenergize the clutch magnet 110 and the timer motor over contacts124 as previously explained.

Thereafter the cycle of timed spray is repeated with the counter 68prevented from operating as explained until the timer motor M1 steps camC1 to its home position. The counter is then again rendered effectiveand it counts out a total predetermined web length as previouslyexplained, whereafter the timer is again rendered ineffective.

The off time is thus independent of the speed at which the web istraveling and since the web length that passes roll 46 usuallyconstitutes the major portion of the web length for the entire cycle,the thickness of the coating is maintained relatively constantirrespective of web speed.

It will be appreciated that the spray time remains constant unlessaltered by the operator and, therefore, the total web length passing theroll for each spray cycle will depend on both the count and the spraytime. The web length passing during the count cycle is constant andsince the greater portion of the web passes during the count cycle anychanges in web speed are reflected only to a relatively small degree bychanges in web length over the entire spray cycle. This change isrelatively small as may be seen from the following figures. If

the web is traveling at 4,000 feet per minute, to rotate an 8- inchdiameter roll at somewhat less than 2,000 rpm, the six switch actuatingassemblies will make less than one revolution per two-thirds of a secondwith a 50-to-l gear reduction. With the counter 68 set for 8 counts, thedry cfi cle is approximately 1 second and 66 feet of web passes the to46 during the dry cycle, while a typical spray time is one-third secondduring which 22 feet of web pass the roll. A total of approximately 88feet pass the roll in one full cycle. Now, if the web speed falls to aslow as 2,000 feet per minute, the web length passing the counter isconstant at 66 feet but only l 1 feet of web passes during the one-thirdsecond spray cycle. This reduces the total web length in the cycle to 77feet; however, this is relatively small reduction as compared with thetotal length per cycle and due to the characteristics of the absorbentroll the coating thickness will remain relatively constant.

If, on the other hand, the web is moving at 2,000 feet per minute, theswitch assemblies are rotating at approximately one revolution per 6seconds. With the counter 68 set for 12 counts, approximately 88 feet ofweb pass during the dry portion of the cycle. With the spray cycle setfor two-thirds of a second about 22 additional feet of web passes. Now,if the web speed increases to 4,000 feet per minute or 66 feet persecond, there will still be 88 feet of web passing during the dry cycleand approximately 44 feet of web during the spray cycle so that thevariation in total web length is only 22 feet per total cycle even ifthe web speed doubles. By operating the counter only when the spraycycle is off and by rendering the dry portion of the cycle relativelylong and constant, a selected uniform coating thickness is provided overa relatively large range of web speeds.

In the described system either the spray cycle or the dry cycle may bevaried as desired. Thus, the timer may provide up to 10 seconds of spraytime in one-third of a second increments, and the counter may provide upto 40 counts before energizing the timer so than extremely wide range ofcoating thicknesses can be provided under a large variety of conditrons.

The foregoing constitutes a description of one embodiment of a webcoating system or method whose inventive concepts are believed set forthin the accompanying claims.

What is claimed is:

l. A web coating method for controlling the amount of liquid for unitarea deposited on a moving web from an absorbent roll comprising thesteps of repetitively counting the passage of a plurality ofpredetermined lengths of web, spraying said liquid on said roll for aselected time period in response to the counting of each plurality ofpredetermined web lengths while preventing the counting of said weblengths only for each said selected time periods.

2. The web coating method claimed in claim 1 in which both the pluralityof predetermined web lengths and said time period are selected toprovide a greater total length of web passing said roll while countingsaid lengths than when spraying said roll irrespective of web speed.

3. A web coating method for controlling the amount of oil sprayed on anabsorbent roll for transfer to a moving metal web comprising the stepsof operating a counter in response to each passage of a predeterminedweb length past a known position until said counter counts a selectednumber of web lengths passing said position, thereafter disabling saidcounter while spraying said roll with said oil for a selected timeperiod, and thereafter terminating said oil spray and reoperating saidcounter for counting said selected number of said web lengths tothereafter again disable said counter and spray oil on said roll forsaid selected time period.

a: t a a:

2. The web coating method claimed in claim 1 in which both the pluralityof predetermined web lengths and said time period are selected toprovide a greater total length of web passing said roll while countingsaid lengths than when spraying said roll irrespective of web speed. 3.A web coating method for controlling the amount of oil sprayed on anabsorbent roll for transfer to a moving metal web comprising the stepsof operating a counter in response to each passage of a predeterminedweb length past a known position until said counter counts a selectednumber of web lengths passing said position, thereafter disabling saidcounter while spraying said roll with said oil for a selected timeperiod, and thereafter terminating said oil spray and reoperating saidcounter for counting said selected number of said web lengths tothereafter again disable said counter and spray oil on said roll forsaid selected time period.